_{RTG 2905 Colloquium}

High-performance time-resolved photoemission experiments of quantum materials

I will discuss our work coupling MHz, kW light sources with momentum microscopy to enable efficient time- and angle-resolved photoemission (tr-ARPES) studies. I will first examine the dynamics of intra- and interlayer excitons in twisted van der Waals heterobilayers. I will then discuss our current work on a new spectrometer to probe ultrafast surface photochemistry in situ with the extension of tr-ARPES beyond ultrahigh vacuum towards more realistic chemical environments.